Double-face velour fabric articles having improved dynamic insulation performance

ABSTRACT

A double-face velour fabric article consists of a fabric body having a technical face formed by a filament stitch yarn and a technical back formed by a filament loop yarn. The filament stitch yarn includes a heat sensitive material, e.g. a hot melt material or a heat shrinkable material, and/or an elastomeric material, such as spandex. The fabric body has a velour surface formed at both the technical back and the technical face. Raised fibers of at least one of the technical face and the technical back may be entangled, including in and/or through interstices of the fabric body, toward the other of the technical face and the technical back, e.g., by a hydroentanglement process applied after finishing. The fabric body has permeability of about 80 ft 3 /ft 2 /min, or less, under a pressure difference of ½ inch of water across the fabric body.

This application is a divisional (and claims the benefit of priorityunder 35 USC 120) of U.S. application Ser. No. 09/982,720, filed Oct.18, 2001, now pending, which is a continuation-in-part of U.S. Ser. No.09/883,643, filed Jun. 18, 2001, now abandoned which is a divisional ofSer. No. 09/347,825, filed Jul. 2, 1999, now abandoned. The disclosureof the prior application is considered part of (and is incorporated byreference in) the disclosure of this application.

This invention relates to double-face velour fabric articles, and, moreparticularly, to double-faced velour fabric articles having improveddynamic insulation performance due to relatively greater densificationand tortuosity.

BACKGROUND

Double-face velour fabric articles having opposite fleece or raisedsurfaces, e.g., achieved by processes of sanding, brushing and/ornapping, are known to have good insulation performance under staticconditions, i.e., in calm or still air with no wind blowing through thefabric. However, the insulating performance of these fabric articlesdrops rapidly under dynamic conditions, i.e., in a chilling wind. As aresult, a consumer wearing a double-face velour fabric article willoften find it necessary to also wear a shell, e.g., of woven nylon orother low permeability material, when conditions are likely to be windy.

It is also known to increase the thermal insulation performance ofdouble-face velour fabric articles by incorporating a relatively coarserstitch yarn and/or by tightening the stitch. However, these approachesresult in fabric articles with very poor stretch, increased stiffnessand increased weight.

SUMMARY

According to one aspect of the invention, a double-face velour fabricarticle comprises a fabric body having a technical face formed by afilament stitch yarn and a technical back formed by a filament loopyarn, the filament stitch yarn comprising heat sensitive material, thefabric body having a velour surface formed at both the technical backand the technical face, and the heat sensitive material responding toapplication of heat during processing to increase tortuosity with aresult of the fabric body having permeability of about 80 ft³/ft²/min orless under a pressure difference of ½ inch of water across the fabricbody (according to the testing method of ASTM Designation: D 737-96,“Standard Test Method for Air Permeability of Textile Fabrics,” theentire disclosure of which is incorporated herein by reference).

Preferred embodiments of this aspect of the invention may include one ormore of the following additional features. The heat sensitive materialis preferably selected from the group consisting of polypropylene,polyester, and polyamide. The heat sensitive material comprises heatshrinkable material, preferably selected from the group consisting ofpolyester, polypropylene, and polyamide. The heat sensitive materialresponds to application of dry heat and/or to application of wet heat,e.g. steam or hot water, e.g. at about 212° F. to about 450° F. appliedfor about 2 minutes to about 60 minutes. The filament stitch yarncomprises elastomeric material, e.g. spandex. Filaments of the heatsensitive material and filaments of the elastomeric material arecommingled or plaited together. The filament stitch yarn is a cored yarncomprising a core and a sheath, the sheath comprising hot melt material.The core material is preferably selected from the group consisting ofpolyester and nylon, and the hot melt material is preferably selectedfrom the group consisting of polypropylene, polyester and polyamide. Thefilament loop yarn is split, e.g. by application of heat, e.g. the loopyarn of fine denier fibers or filaments comprises an “islands-in-sea”construction, or by application of a chemical, e.g. caustic soda, or bymechanical action, e.g. napping, to release multiple small diameterfilaments. The filament loop yarn and/or the filament stitch yarn istextured. Raised fibers of the velour surface, of at least one of thetechnical face and the technical back, is entangled, including in and/orthrough interstices of the fabric body toward the other of the technicalface and the technical back. Raised fibers of the technical back areentangled, including in and/or through interstices of the fabric body,toward the technical face.

According to another aspect of the invention, a double-face velourfabric article comprises a fabric body having a technical face formed bya filament stitch yarn and a technical back formed by a filament loopyarn, the filament stitch yarn comprising elastomeric material, thefabric body having a velour surface formed at both the technical backand the technical face, and the fabric body having permeability of about80 ft³/ft²/min or less under a pressure difference of ½ inch of wateracross the fabric body.

Preferred embodiments of both of these aspects of the invention mayinclude one or more of the following additional features. Theelastomeric material comprises spandex. The fabric body has permeabilityof about 70 ft³/ft²/min or less. Raised fibers of the velour surface ofat least one of the technical face and the technical back is entangled,including in and/or through interstices of the fabric body toward theother of the technical face and the technical back. Preferably, raisedfibers of the technical back are entangled, including in and/or throughinterstices of the fabric body, toward the technical face. At least oneof the filament stitch yarn and the filament loop yarn is a yarn of finedenier filaments or fibers.

According to another aspect of the invention, a double-face velourfabric article comprises a fabric body having a technical face formed bya filament stitch yarn and a technical back formed by a filament loopyarn, the fabric body having a velour surface formed at both thetechnical face and the technical back, with raised fibers of the veloursurface of at least one of the technical face and the technical backentangled, including in and/or through interstices of the fabric bodytoward the other of the technical face and the technical back, thefabric body having permeability of about 80 ft³/ft²/min or less under apressure difference of ½ inch of water across the fabric body.

According to still another aspect of the invention, a double-face velourfabric article comprises a fabric body having a technical face formed bya filament stitch yarn and a technical back formed by a filament loopyarn, the fabric body having a velour surface formed at both thetechnical face and the technical back, with the fabric body havingpermeability of about 80 ft³/ft²/min or less under a pressure differenceof ½ inch of water across the fabric body, wherein, after finishing, atleast one of the technical face and the technical back is subjected tohydroentanglement to entangle raised fibers of the velour surface,including in and/or through interstices of the fabric body, thereby todensify the fabric body and increase tortuosity.

In preferred embodiments of both aspects of the invention, raised fibersof the technical back are entangled, including in and/or throughinterstices of the fabric body, toward the technical face, and/or atleast one of the filament stitch yarn and the filament loop yarn is ayarn of fine denier filaments or fibers.

According to yet another aspect of the invention, a method of forming adouble-face velour fabric body comprises the steps of: joining afilament loop yarn and a filament stitch yarn to form a fabric prebody,the filament stitch yarn forming a technical face of the fabric prebodyand the filament loop yarn forming a technical back of the fabricprebody, the filament stitch yarn comprising heat sensitive material,finishing the technical face and the technical back of the fabricprebody, thereby to form a double-face velour fabric body havingopposite velour surfaces, and exposing the fabric body to heatingsufficient to cause a response by the heat sensitive material, therebyto increase tortuosity with a result of the fabric body havingpermeability of about 80 ft³/ft²/min or less under a pressure differenceof ½ inch of water across the fabric body.

According to another aspect of the invention, a method of forming adouble-face velour fabric body comprises the steps of: joining afilament loop yarn and a filament stitch yarn to form a fabric prebody,with the filament stitch yarn forming a technical face of the fabricprebody and the filament loop yarn forming a technical back of thefabric prebody, finishing the technical face and the technical back ofthe fabric prebody, thereby to form a double-face velour fabric bodyhaving opposite velour surfaces, and entangling raised fibers of atleast one of the technical face and the technical back, including inand/or through interstices of the fabric body, thereby to increasedensity and tortuosity of the fiber body, the fabric body havingpermeability of about 80 ft³/ft²/min or less under a pressure differenceof ½ inch of water across the fabric body.

Preferred embodiments of this aspect of the invention may include one ormore of the following additional features. The method comprises thefurther step of entangling the raised fibers in a process ofhydroentanglement, by directing fine, high-pressure water jets upon atleast one of the technical face and the technical back. The methodcomprises the further step of directing fine, high pressure jets (e.g.,water jets or air jets) upon the technical back, to cause raised fibersof the velour surface of the technical back to entangle, including inand/or through interstices of the fabric body, toward the technicalface. The filament stitch yarn comprises heat sensitive material, andthe method comprises the further step of exposing said fabric body toheating sufficient to cause a response by the heat sensitive material,thereby to increase tortuosity.

Preferred embodiments of both aspects of the invention may include oneor more of the following additional features. The method comprisesexposing the fabric body to the heating sufficient to cause a responseby the heat sensitive material during dyeing and/or during finishing.The method comprises exposing the fabric body to dry heat and/or to wetheat, e.g. steam or hot water. The method comprises exposing the fabricbody to heating sufficient to cause a response by the heat sensitivematerial for about 2 minutes to about 60 minutes at about 212° F. toabout 450° F. The method comprises exposing the fabric body to heatingsufficient to cause a response by the heat sensitive material, therebyto increase tortuosity with a result of the fabric body havingpermeability of about 70 ft³/ft²/min or less. The method comprisesjoining a filament loop yarn and a filament stitch yarn, the filamentstitch yarn comprising elastomeric material, e.g., spandex.

According to still another aspect of the invention, a method of forminga double-face velour fabric body comprises the steps of: joining afilament loop yarn and a filament stitch yarn to form a fabric prebody,the filament stitch yarn forming a technical face of the fabric prebodyand the filament loop yarn forming a technical back of the fabricprebody, the filament stitch yarn comprising elastomeric material, e.g.,spandex, and finishing the technical face and the technical back of thefabric prebody, thereby to form a double-face velour fabric body havingopposite velour surfaces and permeability of about 80 ft³/ft²/min orless under a pressure difference of ½ inch of water across the fabricbody.

An objective of the invention is to provide double-face velour fabricarticles having improved dynamic insulation performance while avoidingincreased weight and/or loss of stretch and/or loss of flexibility. Afurther objective is to provide double-face velour fabric articles thatmay be worn in chilling, windy conditions without markedly diminishedinsulation performance. Generally, tortuosity, and therefore density, isincreased by using heat-sensitive and/or elastomeric materials in thestitch yarns and entangling the loop yarn fibers.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 is a somewhat diagrammatic end section view of a double-facefabric prebody, e.g., as formed in a reverse plaiting circular knittingprocess.

FIG. 2 is a somewhat diagrammatic end section view of a double-facevelour fabric article of the invention formed by finishing thedouble-face fabric prebody of FIG. 1; and

FIG. 3 is a somewhat diagrammatic end section view of a prior artdouble-face velour fabric article that is comparable to the double-facevelour fabric article of FIG. 2.

FIG. 4 is a perspective view of a segment of a circular knittingmachine, and FIGS. 5-11 are sequential views of a cylinder latch needlein a reverse plaiting circular knitting process, e.g., for use informing the double-face fabric prebody of FIG. 1.

FIG. 12 is a somewhat diagrammatic end section view of a double-facevelour fabric article being subjected to a process of hydroentanglement;and

FIG. 13 is a similar, somewhat diagrammatic end section view of aresulting double-face velour fabric article of the invention, havingimproved dynamic insulation performance.

FIG. 14 is a plot of curves showing the relationship between change ineffective thermal insulation and wind velocity for covers or fabrics ofdifferent permeability (P. Larose, “The Effect of Wind on the ThermalResistance of Clothing with Special Reference to the Protection Given byCoverall Fabrics of Various Permeabilities,” Canadian Journal ofResearch, Vol. 25, Sec. A, No. 4, (July 1947), pp. 169-190.).

FIGS. 15-20 are somewhat diagrammatic end section views of otherembodiments of double-face velour fabric articles of the inventionformed of filament stitch yarns and/or filament loop yarns including orconsisting largely of materials with characteristics selected forimproving dynamic insulation performance of the fabric article, namelyheat sensitive materials, elastic materials and/or combinations thereof.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

Referring to FIG. 1, a double-face fabric prebody 12, e.g., for use informing a double-face velour fabric article 10 of the invention (FIG.2), is formed by joining a stitch yarn 14 and a loop yarn 16 in astandard reverse plaiting circular knitting (terry knitting) process(see FIGS. 4-11), e.g., as described in Knitting Technology, by David J.Spencer (Woodhead Publishing Limited, 2nd edition, 1996), the entiredisclosure of which is incorporated herein by reference. In the terryknitting process, the stitch yarn 14 forms the technical face 18 of theresulting fabric prebody 12 and the loop yarn 16 forms the oppositetechnical back 20, where it is formed into loops 22. In the fabricprebody 12 formed by reverse plaiting circular knitting, the loop yarn16 extends outwardly to overlie and cover the stitch yarn 14 at thetechnical face 18.

The loop yarn 16 forming the technical back 20 of the knit fabric body12 can be made of any synthetic or natural material. The cross sectionand luster of the fibers or filaments may be varied, e.g., as dictatedby requirements of the intended end use. The loop yarn 16 can be atextured or flat filament or, preferably, a yarn of fine denierfilaments or fibers (e.g., 1.5 dpf or lower), with a textured yarn beingpreferred for relatively greater dynamic insulating effect, as discussedbelow. The loop yarn overall denier is typically in the range of about70 denier to 300 denier, with a preferred count of about 150 denier. Atthe preferred count, the filament count range is from about 100filaments to 300 filaments, therefore providing a denier per filament(dpf) of from 1.5 to 0.5, respectively. A relatively smaller dpf, e.g. 1dpf, is preferred for relatively greater dynamic insulating effect, aswill be discussed below. A preferred commercial loop yarn is a 150/132denier textured polyester yarn of fine denier filaments or fibers with adpf of 1.14, e.g. as available from UNIFI, Inc., of Greensboro, N.C.

The stitch yarn 14 forming the technical face 16 of the knit fabric body12 can be also made of any type of synthetic or natural material in atextured or flat filament yarn, with a textured yarn being preferred forrelatively greater dynamic insulating effect. The range of stitch yarncount denier is typically between about 50 denier to 150 denier. Wherethe loop yarn is 150/132 textured, the preferred stitch yarn count isabout 100 denier, and the filament count ranges from about 34 filamentsto 200 filaments, i.e. 100/34 to 100/200, resulting in dpf from about 3dpf to 0.5 dpf, with relatively finer filaments being preferred, again,for relatively greater dynamic insulating performance. A preferredstitch yarn is 100/136 denier textured polyester with about 0.7 dpf,e.g. as available commercially from UNIFI, Inc. Another preferred yarnis 130/408 denier textured polyester with about 0.3 dpf, e.g. asavailable from Hyosung, Inc., of Seoul, Korea.

From these examples, it can be seen that, for achieving markedlyimproved dynamic insulating performance, use of a textured 150/132 loopyarn and a textured 100/136 stitch yarn is preferred.

In comparison, in a prior art double-face velour fabric article (100,FIG. 3) without the improved dynamic insulation performance of thepresent invention, a typical stitch yarn 102 is 70/34 denier filamenttextured polyester, with individual fiber fineness of greater than 2.0dpf, e.g. as available commercially from UNIFI, Inc.

In a preferred method of the invention, the fabric prebody 12 is formedby reverse plaiting on a fine cut circular knitting machine (e.g., 28cut). This is principally a terry knit construction, where segments 22of the loop yarn 16 cover the stitch yarn 14 on the technical face 18and loops 23 of the loop yarn 16 form loops 23 at the technical back 20of the fabric prebody 12 (see FIG. 1).

The fabric prebody 12 is next subjected to finishing. During thefinishing process, the technical face and technical back surfaces 18,20, respectively, of the fabric prebody 12, with the segments 22 of loopyarn 16 overlying the stitch yarn 14 at the technical face surface 18and the loops 23 formed at the technical back surface 20, go through afinishing process such as sanding, brushing and/or napping, to generatea velour 24, 26. The yarn fibers are raised at both faces of the fabricprebody 12 (FIG. 1), including the technical face 18 and the technicalback 20, to form the velour 24, 26 at each face of the fabric body 30 ofthe double-face velour fabric article 10 (FIG. 2) of the invention. Thefabric prebody 12 and/or fabric body 10 may also be treated, e.g.,chemically, to make it hydrophobic.

Referring to FIG. 12, after finishing, the fabric article 10 is nextsubjected to a process of hydroentanglement, such as employed infabrication of spun staples yarn and in the fabrication of non-wovenfabrics. During this process, fine, high-pressure water jets 32 (or airjets) are directed onto, e.g., the technical back 20 of the fabricarticle 10. In this manner, raised fibers 34 of the velour surface ofthe technical back 20 are entangled, including in and/or throughinterstices of the fabric body 30, toward the technical face 18. Thehydroentanglement process thus serves to densify the velour surface,resulting in the double-face fabric article 40 (FIG. 13),advantageously, without substantial increase in bulk or thickness, forimproved dynamic insulation, i.e. against through-flow of air, e.g., ina chilling wind. By way of example only, after finishing, the technicalback 20 of a double-face velour fabric article 10 may be treated byhydroentanglement using fine, high-pressure water jets 32, e.g., withwater applied at 100 m/sec to 350 m/sec through jets having apertures of0.01 mm to 1.0 mm diameter. Alternatively, raised fibers of thetechnical face may be entangled in and/or through interstices of thefabric body, toward the technical back.

Entangling raised fibers of the technical back, i.e., of the loop yarn,including in and/or through interstices of the fabric body, toward thetechnical face, results in relatively greater densification andtherefore greater tortuosity, e.g., as compared to entanglement ofraised fibers of the technical face, including in and/or throughinterstices of the fabric body, toward the technical back. Entanglingfrom back to face, in addition to resulting in a relatively greaterincrease in tortuosity, also increases smoothness of the fabric/garmentouter surface, while entangling from face to back increases tortuosityand increases smoothness of the fabric/garment inner surface.

Fabric performance and aesthetics of the fabric article 40 can also beadjusted by selection of knitting gauge (e.g., in the range of about 18to about 36, and preferably about 28), yarn type (e.g., preferablytextured, or flat filament), yarn denier (e.g., about 70 to about 300,and preferably about 100), fiber denier (e.g., about 0.3 to about 1.5,and preferably about 1.0), etc. Adjustment of jet speed and/or aperturesize, e.g., within the ranges mentioned above, can further or instead beemployed to adjust fabric performance and/or aesthetics.

The fabric article 40 is thereafter heat set to stabilize the fabricarticle width.

In this and other embodiments of the invention described below, heat maybe applied to the fabric body, e.g. dry heat and/or wet heat, such ashot water or steam, e.g. during finishing or dyeing. As mentionedelsewhere, the stitch yarn (and/or the loop yarn) may include heatsensitive and/or elastomeric materials.

In a resulting double-face velour fabric article 10 of this embodimentof the invention, the overall density, i.e., weight per length, of thefilament stitch yarn 14 is closely comparable to stitch yarn 102 used ina comparable prior art fabric article 100 having velour 104, 106 at theopposite faces. The diameter of the filament stitch yarn 14 may beslightly greater than that of the prior art stitch yarn 102 (likely dueto increased filament-to-filament engagement of the filaments of thefilament stitch yarn 14). The yarn count and gauge of the double-facevelour fabric article 10 of the invention are also substantially thesame as those for the comparable prior art fabric article 100. As aresult, the weight and stretch performance of the double-face velourfabric article 10 of the invention is closely comparable to the weightand stretch of the prior art double-face velour fabric article 100 ofthe same gauge and yarn count.

The fact that the weight density of the filament stitch yarn 14 and thestitch yarn 102 are the same indicates that the ratio of yarn materialto open volume for each of the respective articles is also approximatelythe same. However, in the filament stitch yarn 14, and in the resultingdouble-face velour fabric article 10 of the invention, the average crosssectional area of the individual filaments is considerably less that theaverage cross sectional area of filaments in the stitch yarn 102employed in the comparable prior art fabric article 100, e.g. the denierper filament (dpf) of the preferred filament stitch yarn 14 is about 0.7dpf, as compared to 3.0 dpf for the stitch yarn 102 of comparable priorart fabric article 100. As a result, the paths for passage of air, e.g.,a chilling wind, through double-face velour fabric article 10 of theinvention, while relatively more numerous, are also considerably smallerand relatively more tortuous, as compared to a comparable prior artdouble-face velour fabric article 100. The enhanced performance of thefabric article of the invention is achieved by increasing the yarn countand the filament count to make the paths through the fabric moretortuous, thus making it more difficult for air, i.e., a chilling wind,to penetrate quickly through the double-face velour fabric article 10 ofthe invention. As a result, the dynamic insulation performance of thedouble-face velour fabric of the invention is dramatically increasedover the prior art.

In FIG. 14, there is reproduced a plot of curves showing therelationship between change in effective thermal insulation and windvelocity for covers or fabrics of different permeabilities, as appearedin an article by P. Larose, entitled “The Effect of Wind on the ThermalResistance of Clothing with Special Reference to the Protection Given byCoverall Fabrics of Various Permeabilities,” which appeared in CanadianJournal of Research (Vol. 25, Sec. A, No. 4, (July 1947), pp. 169-190),the entire disclosure of which is incorporated herein by reference. Thepermeabilities of the materials tested varied between 0 and 193ft³/ft²/min under a pressure difference of ½ inch of water across thefabric.

In particular, it can be seen in the plot that at zero wind velocitythere is relatively little difference in insulating performance amongthe materials tested. The dynamic insulating performance for each of thematerials tested also decreased with increasing wind velocity. However,as may be seen in the plot, the rate of decrease in dynamic insulatingperformance was much more precipitous in fabrics of relatively greaterpermeability, i.e. as permeability increased, the rate of loss ofdynamic insulating performance with increasing wind velocity wasrelatively smaller for fabrics of low permeability, as compared tofabrics having relatively greater permeability.

In Table A (below), the improvement in dynamic insulation performance ofdouble-face velour fabric articles 10 (FIG. 2) of the invention in achilling wind can easily be seen when compared to the performance of acomparable prior art double-face velour fabric article 100 (FIG. 3). Inparticular, the double-face velour fabric article 10 of the inventionhas considerably better dynamic insulating performance, and good static(no wind) and dynamic (windy) insulation performance, due to theincreased tortuosity of air paths through the fabric, with good stretchproperties and light weight.

TABLE A A1 A2 B1 B2 Loop Yarn 150/100 150/132 150/100 150/132 texturedtextured textured textured Stitch Yarn 100/34 100/34 100/34 100/34textured textured textured textured Width 58-inch 58-inch 54-inch54-inch cuttable cuttable cuttable cuttable Dynamic 100-110 60-70 70-8050-60 Insulating Performance Compare: A1 to A2 A2 has finer loop yarn,and therefore relatively better dynamic insulating performance. Compare:A1 to B1 B1 has narrower width, and therefore better dynamic insulatingperformance. Compare: A1 to B2 B2 has finer loop yarn, and thereforebetter dynamic insulating performance. Compare: A1 to B2 B2 has finerloop yarn and narrower width, and therefore better dynamic insulatingperformance

The word “tortuosity” is used to describe the fabric property enhancedaccording to this invention by increasing yarn count and filament count.The paths through the fabric are made more “tortuous” than those ofprior art fabrics, and greater “tortuosity” results in greater dynamicinsulating effect. In addition, if a given fabric body is subjected toless than normal stretching, resulting in reduced final width of thefabric (i.e., the width resulting after heat setting of the fabricduring the finishing process), the higher, still, the dynamic insulatingperformance of the resulting fabric article of the invention.

In other preferred embodiments, fabric articles of the invention havingrelatively greater densification and tortuosity, and therefore increaseddynamic insulation performance for enhanced protection from windpenetration, are achieved by incorporation of stitch yarns and/or loopyarns of predetermined selected characteristics. For example, stitchyarns and/or loop yarns including, or formed largely of, heat sensitivematerials, e.g. hot melt or heat shrinkable materials, and/orelastomeric materials, such as spandex, may be employed.

For example, referring now to FIG. 15, in a preferred embodiment, afabric article 30 of the invention formed by reverse plaiting on a finecut circular knitting machine includes a stitch yarn 32 and a loop yarn34 finished into a velour 36, 38 at the opposite surfaces. The stitchyarn 32 includes, or consists largely of, yarn or filaments of heatsensitive material 33, e.g. heat shrinkable material, or hot meltmaterial (typically commingled (e.g., blended) with other fiber thatwill maintain yarn integrity after heat treatment). Suitable heatsensitive materials include polypropylene, polyester, polyamide, and thelike, preferably with high shrinkage, e.g., about 5% to about 50% afterabout 2 minutes to about 60 minutes at about 212° F. to about 450° F.Heat is thereafter applied to the fabric article, e.g., dry heat and/orwet heat, such as hot water or steam, e.g. during dyeing and/orfinishing. Upon exposure to heat, the hot melt material fuses to narrowor fill interstices between the yarns filaments, and the heat shrinkablematerial shortens and thickens, and/or reduces in effective length, thusto reduce the paths for passage of chilling wind through the fabric andthereby increase the tortuosity and the dynamic insulation performanceof the fabric article 30 of the invention.

Referring next to FIG. 16, in another embodiment, in a fabric article 40of the invention, the stitch yarn 42 comprises a cored yarn 43 having acore formed, e.g., of polyester or nylon, with a sheath formed of a heatsensitive material, e.g., a hot melt material, such as polypropylene,polyester or polyamide, e.g. as available commercially from EngineeredYarn Company, of Fall River, Mass. During heating of the fabric articleof this embodiment, e.g. during dyeing and/or finishing, the hot meltmaterial of the sheath fuses, thus increasing the tortuosity and furtherreducing the paths for passage of chilling wind through the fabric andimproving the dynamic insulation performance of the fabric article 40 ofthe invention.

Referring now to FIG. 17, in a fabric article 50 of the invention, thestitch yarn 52 includes elastomeric material 53, e.g. such as spandex.The elastomeric material 53 in the stitch yarn 52 also provides forrelatively greater densification and tortuosity, and therefore increaseddynamic insulation performance for enhanced protection from windpenetration, as well as providing for fabric stretch and enhanced wearercomfort.

Referring now to FIG. 18, a fabric article 60 of the invention may alsobe formed of stitch yarns 62 including or consisting largely ofcombinations of heat sensitive materials 63 and elastomeric materials65. For example, stitch yarns employed in the fabric article 60 mayinclude fibers or filaments of different characteristics that have beencommingled or plaited together.

Referring to FIG. 19, in another embodiment, a fabric article 70 of theinvention is formed of loop yarns 72 of standard denier that, uponapplication of heat, e.g., during dyeing and/or finishing, split axiallyinto multiple, elongated fibers or filaments. The result is a reductionor narrowing of paths for passage of chilling wind through the fabric,to increase tortuosity and dynamic insulation performance of the fabricarticle 70. The loop yarns may be caused to split also by application,e.g., of a chemical treatment, e.g. caustic soda, or by application of amechanical action, e.g. napping.

Referring finally to FIG. 20, in yet another embodiment, a fabricarticle 80 of the invention is formed of loop yarns 82 having an“islands-in-sea” construction. Namely, the loop yarns 82 are formed of ahot melt polymeric body (“sea”) containing multiple filaments(“islands”) of small diameter, e.g. 0.01 to 0.03 denier. Uponapplication of heat to the fabric article 80, e.g., during dyeing and/orfinishing, the hot melt material melts to release the individual, smalldiameter filaments. Again, the release of the small filaments results inincreased tortuosity and dynamic insulation performance of the fabricarticle 80.

Due to the increased tortuosity, including after heat treatment, afabric article of the invention formed with stitch yarns including orconsisting largely of heat sensitive materials and/or elastomericmaterials, such as spandex, and/or loop yarns formed of heat sensitivematerials and/or elastomeric materials such as spandex, and/or coredyarns having a sheath of hot melt material, have enhanced dynamicinsulation performance, e.g. as compared to a prior art fabric article100 (FIG. 3) having the same weight. As a result, the fabric articles ofthe invention are particularly suited for use, e.g., in lightweightclothing and the like for use in extreme conditions of chilling wind andcold temperature.

Examples of fabric articles of the invention formed with heat sensitivematerials and/or elastomeric materials will now be described:

EXAMPLE 1

A fabric article of the invention, designated S/7380, was formed of astitch yarn consisting of 150/34 POWERSTRETCH™ heat shrinkable texturedpolyester, available from UNIFI, Inc., and a loop yarn consisting of150/132 textured polyester. After exposure to heat, the air permeabilityof the finished fabric article, tested according to ASTM-737, was 70ft³/ft²/min.

EXAMPLE 2

Another fabric article of the invention, designated E555P, was formed ofa stitch yarn consisting of 50/36 textured polyester with 20 denierspandex on every other end plaited with 50/36 textured polyester and aloop yarn consisting of 150/132 textured polyester. After exposure toheat, the air permeability of the finished fabric article, testedaccording to ASTM-737, was 59 ft³/ft²/min.

EXAMPLE 3

Yet another fabric article of the invention, designated E657Y, wasformed of a stitch yarn consisting of 50/36 textured polyestercommingled with 40/20 textured polypropylene and a loop yarn consistingof 100/96 textured polyester. After exposure to heat, the airpermeability of the finished fabric article, tested according toASTM-737, was 38-40 ft³/ft²/min.

EXAMPLE 4

Another fabric article of the invention, designated E667Q, was formed ofa stitch yarn consisting of 100/34 POWERSTRETCH™ heat shrinkabletextured polyester and a loop yarn consisting of 100/96 texturedpolyester. After exposure to heat, the air permeability of the finishedfabric article, tested according to ASTM-737, was 60-70 ft³/ft²/min.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Forexample, any type of yarn may be employed. Also, other suitable methodsof constructing a velour fabric article of the invention may beemployed. For example, in the preferred embodiment described above, theconstruction provided by reverse plaiting is employed in order to exposethe loop yarn 16 for finishing at both surfaces of the fabric body, withsegments 22 of the loop yarn 16 overlaying the stitch yarn 14 at thetechnical face 18 and formed into loops 23 at the technical back 20.This is preferred, for reasons of dynamic insulation performance, over aconstruction in which only the loop yarn is finished. However, whereimprovement of dynamic insulation performance is not the primary or anoverwhelming consideration, a construction exposing the stitch yarn andthe loop yarn side by side for finishing at one or both surfaces of afabric body may be preferred. In embodiments of fabric articles of theinvention formed with heat sensitive materials, heat may be appliedother than or in addition to during dyeing and/or finishing, e.g.,before, after, or between these stages of manufacture. Also, referringagain to FIG. 13, a double-face velour fabric article 40 of theinvention may be formed by applying the hydroentanglement process to thetechnical face 18 and/or the technical back 20, e.g., using fine,high-pressure water jets 32 and/or 32′, respectively.

As mentioned above, a fabric article with stitch yarn and/or loop yarncomprising heat sensitive and/or elastomeric material may also beentangled or hydroentangled according to the invention.

Accordingly, other embodiments are within the scope of the followingclaims.

What is claimed is:
 1. A method of forming a double-face velour fabricbody, said method comprising the steps of: joining a filament loop yarnand a filament stitch yarn to form a fabric prebody, the filament stitchyarn forming a technical face of the fabric prebody and the filamentloop yarn forming a technical back of the fabric prebody, the filamentstitch yarn comprising heat sensitive material, finishing said technicalface and said technical back of the fabric prebody, thereby to form adouble-face velour fabric body having opposite velour surfaces, andexposing said fabric body to heating sufficient to cause a response bysaid heat sensitive material, thereby to increase tortuosity with aresult of said fabric body having permeability of about 80 ft³/ft²/minor less under a pressure difference of ½ inch of water across the fabricbody.
 2. The method of forming a double-face velour fabric body of claim1, comprising exposing said fabric body to said heating sufficient tocause a response by said heat sensitive material during dyeing.
 3. Themethod of forming a double-face velour fabric body of claim 1,comprising exposing said fabric body to said heating sufficient to causea response by said heat sensitive material during finishing.
 4. Themethod of forming a double-face velour fabric body of claim 1,comprising exposing said fabric body to dry heat.
 5. The method offorming a double-face velour fabric body of claim 1, comprising exposingsaid fabric body to wet heat.
 6. The method of forming a double-facevelour fabric body of claim 5, comprising exposing said fabric body tosteam.
 7. The method of forming a double-face velour fabric body ofclaim 5, comprising exposing said fabric body to hot water.
 8. Themethod of forming a double-face velour fabric body of claim 1,comprising exposing said fabric body to said heating sufficient to causea response by said heat sensitive material for about 2 minutes to about60 minutes at about 212° F. to about 450° F.
 9. The method of forming adouble-face velour fabric body of claim 1, comprising joining a filamentloop yarn and a filament stitch yarn, the filament stitch yarncomprising elastomeric material.
 10. The method of forming a double-facevelour fabric body of claim 1, comprising exposing said fabric body toheating sufficient to cause a response by said heat sensitive material,thereby to increase tortuosity with a result of said fabric body havingpermeability of about 70 ft³/ft²/min or less.
 11. The method of forminga double-face velour fabric body of claim 1, wherein the filament stitchyarn comprises elastomeric material.
 12. The method of forming adouble-face velour fabric body of claim 9, or claim 11, wherein theelastomeric material comprises spandex.